src/core/SkICCPriv.h

/*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef SkICCPriv_DEFINED
#define SkICCPriv_DEFINED

#include "SkColorSpace.h"
#include "SkTypes.h"

// This is equal to the header size according to the ICC specification (128)
// plus the size of the tag count (4).  We include the tag count since we
// always require it to be present anyway.
static constexpr size_t kICCHeaderSize = 132;

// Contains a signature (4), offset (4), and size (4).
static constexpr size_t kICCTagTableEntrySize = 12;

static constexpr uint32_t kRGB_ColorSpace     = SkSetFourByteTag('R', 'G', 'B', ' ');
static constexpr uint32_t kCMYK_ColorSpace    = SkSetFourByteTag('C', 'M', 'Y', 'K');
static constexpr uint32_t kGray_ColorSpace    = SkSetFourByteTag('G', 'R', 'A', 'Y');
static constexpr uint32_t kDisplay_Profile    = SkSetFourByteTag('m', 'n', 't', 'r');
static constexpr uint32_t kInput_Profile      = SkSetFourByteTag('s', 'c', 'n', 'r');
static constexpr uint32_t kOutput_Profile     = SkSetFourByteTag('p', 'r', 't', 'r');
static constexpr uint32_t kColorSpace_Profile = SkSetFourByteTag('s', 'p', 'a', 'c');
static constexpr uint32_t kXYZ_PCSSpace       = SkSetFourByteTag('X', 'Y', 'Z', ' ');
static constexpr uint32_t kLAB_PCSSpace       = SkSetFourByteTag('L', 'a', 'b', ' ');
static constexpr uint32_t kACSP_Signature     = SkSetFourByteTag('a', 'c', 's', 'p');

static constexpr uint32_t kTAG_rXYZ = SkSetFourByteTag('r', 'X', 'Y', 'Z');
static constexpr uint32_t kTAG_gXYZ = SkSetFourByteTag('g', 'X', 'Y', 'Z');
static constexpr uint32_t kTAG_bXYZ = SkSetFourByteTag('b', 'X', 'Y', 'Z');
static constexpr uint32_t kTAG_rTRC = SkSetFourByteTag('r', 'T', 'R', 'C');
static constexpr uint32_t kTAG_gTRC = SkSetFourByteTag('g', 'T', 'R', 'C');
static constexpr uint32_t kTAG_bTRC = SkSetFourByteTag('b', 'T', 'R', 'C');
static constexpr uint32_t kTAG_kTRC = SkSetFourByteTag('k', 'T', 'R', 'C');
static constexpr uint32_t kTAG_A2B0 = SkSetFourByteTag('A', '2', 'B', '0');

static constexpr uint32_t kTAG_CurveType     = SkSetFourByteTag('c', 'u', 'r', 'v');
static constexpr uint32_t kTAG_ParaCurveType = SkSetFourByteTag('p', 'a', 'r', 'a');
static constexpr uint32_t kTAG_TextType      = SkSetFourByteTag('m', 'l', 'u', 'c');

enum ParaCurveType {
    kExponential_ParaCurveType = 0,
    kGAB_ParaCurveType         = 1,
    kGABC_ParaCurveType        = 2,
    kGABDE_ParaCurveType       = 3,
    kGABCDEF_ParaCurveType     = 4,
};

/*
 * Given fn and toXYZD50, generate a decription tag that either includes a hash
 * of the function and gamut or is a special name.
 * Exposed for unit testing and tools.
 */
SkString SkICCGetColorProfileTag(const SkColorSpaceTransferFn& fn,
                                 const SkMatrix44& toXYZD50);
#endif  // SkICCPriv_DEFINED